The researchers at RAND Health and the Greater Los Angeles VA Healthcare System reviewed some 38 studies published between 1966 and 2005 on omega-3 fatty acids, found in some fish and certain vegetables and also sold as dietary supplements.
Previous studies have suggested that people who consume diets rich in omega-3 fatty acids may experience a lower prevalence of some types of cancer.
In many small trials they have tried to assess the effects of omega-3 fatty acids on cancer treatment by adding omega-3 fatty acid to the diet either as omega-3 fatty acid-rich foods or as dietary supplements.
As a result a number of omega-3 fatty acid - containing dietary supplements have appeared on the market claiming to protect against the development of a variety of conditions including cancer, despite studies reporting mixed results.
Catherine H. MacLean, M.D., Ph.D., of RAND Health, Santa Monica, Calif., and colleagues independently abstracted detailed data about the incidence of cancer, the type of cancer, the number and characteristics of the patients, details on the exposure to omega-3 fatty acids, and the elapsed time between the intervention and outcome measurements.
MacLean says there have been few studies that showed a reduced risk of cancer from consuming the fatty acids, but they found even more studies that showed no decrease in cancer risk and even a few that suggested a higher risk.
The team concluded that there is no relationship between omega-3 fatty acids and lower rates of any types of cancer.
The study was published in the Journal of the American Medical Association.
More than 13 million people in the United States, mostly middle-aged and older women, experience loss of bladder control. Overweight women and those with type 2 diabetes have a 50- to 70-percent increased risk of incontinence. In the National Health and Nutrition Examination Survey 2001-2002 sample, one out of three women with diabetes or prediabetic glucose levels reported weekly or more frequent episodes of UI.
Some studies have reported that increased physical activity worsens incontinence, but DPP participants randomly assigned to lifestyle changes, who typically chose walking as their physical activity, did not have increased problems with incontinence.
"Urinary incontinence is a costly, socially isolating condition that impairs quality of life and takes a psychological toll on many women. For women at risk for type 2 diabetes, losing a modest amount of weight is likely to alleviate incontinence, especially stress incontinence," said Leroy Nyberg, M.D., Ph.D., of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), which funded the study.
Nearly 21 million people in the United States--7 percent of the population--have diabetes, the most common cause of blindness, kidney failure, and amputations in adults and a major cause of heart disease and stroke. Type 2 diabetes accounts for up to 95 percent of all diabetes cases. The prevalence of type 2 diabetes has risen dramatically in the last 30 years, due mostly to the upsurge in obesity. In addition, about 40 percent of U.S. adults ages 40 to 74--41 million people--have prediabetes, which raises the risk of developing type 2 diabetes and cardiovascular disease.
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